Electric control mechanism for sound reproducing machines



Jan, 13. 1925. 1,523,343 E. J. JOHNSON ELECTRIC CONTROL MECHANISM FOR SOUND REPRODUCING MACHINES Filed June 1924 5 Sheets-Sheet 1 E. J. JOHNSON ELECTRIC CONTROL MECHANISM FOR SOUND REPRODUCING MACHINES Filed June 9, 192.4 3 Sheets-Sheet 2 Jan, 13. 1925.

1,523,343 E. J. JOHNSON ELECT-RIC CONTROL MECHANISM FOR SOUND REPRODUCING MACHINES Filed June 19, 192A 3 Sheets-Sheet 5 g M F Patented Jan. 13, 1925. r

UNRITAIED STATES: RATENT; caries.

manna. JOHNSON, on SOMERVILLE, MASSACHUSETTS, ASSIGNOB T0 rs-Ann n.

. THAYER, orrsosron, MAssAcHUsE'rTs.

ELECTRIC'OONTROL MECHANISM FOR SOUND REPRODUCING. MACHINES Application filed June 1 9, 1924.- SeriaINo; 721,106.

To all 107mm. it wmg po zwern: V f Be it-known that LEIN'AR J .J OHNSON, a

citizen of 'Somer-ville, county monwe an Improvement in Electric anisms of which the following description, in connection with theaccompanying drawings, is a specification, like characters on the drawings representing like parts in each of the se'v er a1 Views.

Thls invention relates to mechanism for control actuate ling the operation of electrically d sound reproducing machmes of the type employing ausnal turntable bearing the rec ing a sound box and stylus.

0rd, anda swinging tone arm bear- A principal object of the invention is to provide a simple and re ti'cula-r sa ine,

phonograph motor,

liable mechanism requiring no parskill or attention. for operating the that is adapted'to de-energize the and simultaneously apply a-brake when the. tone arm bearing the stylus reaches al ure-determined point on the record that has bee-n previously-established by a preliminary swinging movement of thetone arm to ticular the point where the parrecord to be played ends. A further obgect is. t'oprovide a mechanism of the kind described that is virtually noiseless in operation, that is not apt to i get out of order from careless usage, and that is automatical- 1y adaptableto records of various length. ne foregoing andfother objects and advantages ofi'the invention willwmore fully appear tion taken in connection'with-the panyin tures .of novelty will be appended claims.

from the following detailed descripaccom g drawings, and. the distinctive feapointed out. in the Referring to the drawings Fig.

-1 is a plan view of a. soundreproducing machineequipped with the invention, portionsbe -ngbroken away; and in horizontal section;

2 is'saside elevation thereotwith portions broken away andtin vertieal section Fig. partly control-ling buttonand therefr 3 is a detail partly in elevation and in vertical-section, showing a hand the connections om;

4. is alview, similar to Fig. 3, but ga modified formwherein two hand meshes a small friction wheel 18, borne by the armature shaft 19 of an electric motor 20, this motor being shown as fixed in depending. relation on a bracket support 21 of the housing. Themotor 20 is energized by a circuit 22, in which is interposed a mainiswitch 23. This switch may be of usual.bridging-type, equipped with a bridg ing contact 24 actuated by a sliding rod 25. In accordance withmy invention this switch operating rod has a magnet or solenoid 26 associated therewith, the energization of which is adapted to move the rod 25 to switch-open position. This solenoid is in an auxiliary circuit 27,which is shown as in shunt relation with the motor, though it might be otherwise arranged. In this circuit 27 is. a second circuit breaker or switch, comprising a fixed contact 28 and a movable contact 29, borne by an arm 30 mounted for limited swinging movement on a pivot 31. A light compression. spring 32 normally holds the arm130 in position so that the contacts 28',v 29 :are: separated. Means is pro-- vided whereby the arm 30 is moved to close the circuit-through thecontacts 28, 29, and thus deenergize the motor at the completionvof the playing of a record whether the record :be. a longeror shorter, i. e., whether the recording terminates at a point more or less remote from the center of the record. F or this purpose the arin- 3O has mounted on the pivot 31 thereof-and frictionallyengaged therewith, a. disk plate 33-bearing an arm 34 extending outwardgtowards the axis on -which*the tone arm swings. This plate 33 is held frictionally engaged with the, base of the arm 30 with a moderate degree. of friction pressure by a spring washer engagednnder the head of'the pivot stud 81, and pressing-downward upon the plate.

33. This frictional engagement of the plate 33 with the base of the arm is suflicient to cause the arm 30 to be turned by a movement of the arm 34 so as to bring the contact 29 against the contact 28, but is not.

sufiicient to prevent a further turning adjustment of the arm- 34 with respect to the arm 30. For limiting the angular movement of the plate 33 it is provided with spaced-apart prongs 36, 37 which are adapted to engage a fixed pin 38 borne by the housing. For actuating the arm 34 the tone arm 11 is provided with a depending finger 39 in position to engage said arm as the tone arm nears its inner limit of swinging movement as the playing of a record is completed. To set the device so that the shunt circuit through contacts 28', 29 will be closed and the motor de-ene-rgized at the instant the playing of the record is completed, the'tone arm is first swung inward so that the stylus is at the locality of the in ner end of the recording on the record. This results in first bringing the contact 29 against the contact 28, and then in swinging the arm 34 frictionally with reference to the arm 30 during the completion of such movement of the tone arm,-the parts being thus adjusted so that when the tone arm again reaches this position at the completionof the playing of the record, the contacts 29, 28 will be brought together and the motor deenergized. For setting the arm 34 so that it is in readiness for the described adjustment at each operative movement, a re-setting finger 40 is provided which when the tone arm is swung outward operates to turn the arm 34 frictionally outward with respect to the arm 30. A brake 41 operative upon the frictioirdisk 17 is provided, and connected for synchronous operation with the inotor-controlling switch 23. For this purpose the brake 41 is borne at the inner end of a bar 42 which is pivotedintermediate its length at 43 to a lever 44 which is fulcrumed at 45 at its upper end to the housing and has its lower end engaged with the end of the switch rod 25 as indicated at 46. Thus as the switch rod is moved to open the switch 23, the brake 41 will. be applied to the friction disk 17 to stop the turntable instantly. For resetting the switch and brake to start the machine in operation, the outer end of the bar 42 is pivoted at 47 to a short arm of a. bell crank lever 48 that is fulcrumed at 49 to the housing. The other longer arm of this bell crank lever is engaged as indicated at 50 with one end of a short lever 51 which is pivoted intermediate its length as indicated at 52 to a depending ear of the housing and has its other end pivotally engaged at 53 with the stem of a push button 54. The head 54 of this push button extends a small distance above the top of the housing in poe' ually without resorting to the described automatic stop controlled by the tone arm. For this purpose the lever 51 has itsend which is connected with the lever 48 also engaged by a second push button 55 suitably fitted in the housing and having an exposed head 55 corresponding to the head 54. By merely pressing down upon this head 55 through the described connections the motor is de-energized and the brake applied at any time desired.

I also preferably provide a safety device adapted to protect the main switchtand the shunt or solenoid controlling switch against improper usage by inexperienced or careless operators. To this end I provide means adapted to prevent manual operation of the main switch to close the same by means of the button 54, until such time as the tone arm lever has been moved outward from its point of contact with the arm34 so that the contacts 29, 28 are separated by the action of the spring 32. This may be effected by the provision of a rod 56 slidably fitted in lugs 57 of the housing in position so that the outer end thereof is adapted to rest normally against a side of the lever 51, but in position so that when the button 54 is raised, i. e., in.switchopen position, said rod may be projected outward so as to lie overthe lever 51 and prevent movement thereof to close theswitch until such time as said rod' is withdrawn. The other end of this rod has a depending portion 56 thereof pivotally engaged with one end of a lever58 which is fulcrumed at an intermediate point to a lug of-the housing as indicated at 59. The other end of this lever extends through a somewhat elongated slot 60 formed in a stem 61 which is borne by, and extends downward from the arm 30. A tension coil. spring 62 anchored to a finger 63 depending from the housing engages the end of. the

lever 58 which extends through the slot 60, and tends to draw said lever so as to cause the rod 56 to be projected over the lever 51 when the lever 51 is tilted to permit this. The location of the lever 58 with respect to the slot 60 is such that so long as the arm 30 is in swtioh-open'position, said lever engages the end of such slot and restrains said lever and hence-the rod 56 from movement to position said rod over the lever 5 1',"while so long as the arm 30 is in switch-closed po sition the lever 58 is permitted to move in the slot 60 to permit the location of the rod 56 over the lever 51 in the locking position.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. Apparatus of the kind described, comprising a turntable having an electric mo tor connected to operate the same, a switch in the circuit of said motor having magnetic operating means, an auxiliary circuit in which said magnetic operating means is ineluded, a circuit breaker in said auxiliary circuit, a brake co-operativ-e with said turntable, a tone arm, and meansassociated with said circuit breaker and arranged for adjustment by a preliminary movement of the tone arm, for closing said switch, de-energizing said motor, and applying said brake when the tone arm reaches a predetermined and selective point in the playing of a record on said turntable.

2. Apparatus of the kind described comprising a turntable, a tone arm, a motor connected to operate said turntable having a switch in the circuit thereof, a brake opera tive on said turntable, magnetic means for operating said switch and brake, an auxiliary circuit to which said magnetic means is responsive having a circuit breaker included therein, and means having an element arranged for adjustment by a preliminary movement of the tone arm for operating said circuit breaker to close said auxiliary cirruitand cause de-energization of said motor and of said brake when the tone arm reaches a predetermined and selective point on a record on said turntable.

'3. Apparatus of the kind described comprising a turntable, a swinging tone arm cooperative therewith, an electric motor connected to operate the turntable, a switch controlling said motor, a member frictionally adjustable with respect to a moveable member of said switch, and means borne by the tone arm adapted to engage said member to effect an adjustment thereof by a preliminary movement of the tone arm, and arranged so that when the tone arm again reaches the position to which it was moved preliminarily, in the playing of the record, the motor is deenergized.

4. Apparatus of the kind described comprising a turntable, an operating motor therefor, a tone arm, control connections for said motor embodying a switch, a member frictionally adjustable with respect to a moving member of said switch, means borne by the tone arm in position to engage said member to adjust the same by a preliminary movement of the tone arm whereby said means is adapted to operate said switch and de-energize the motor when the tone arm again reaches the position to which it was preliminarily moved, and means arranged for operation by the tone arm as it is swung outward for starting said motor.

5. Apparatus of the kind described comprising a turntable, an operating motor therefor, a tone arm, control connections for said motor embodying a switch, a member frictionally adjustable with respect to a moving member of said switch, means borne by the tone arm in position to engage said member to adjust the same by a preliminary movement of the tone arm whereby said means is adapted to operate said switch and de-energize the motor when the tone arm again reaches the position to which it was preliminarily moved, means arranged for operation by the tone arm as it is swung outward for starting said motor, and means for locking said motor starting means against opertion until said switch is opened.

In testimony whereof, I have signed my name to this specification.

EINAR J. JOHNSON. 

